- scaling – professional deep cleaning to remove plaque, calculus, and surface stains from teeth, a common treatment for periodontal disease
- sealant – thin, resinous material that is applied to occlusal surfaces of rear molars to help prevent decay
- separator/spacer – small rubber orthodontic ring used to create space between teeth before bands are attached
- sinus graft – bone graft on the maxillary sinus to allow the placement of dental implants
- sleep apnea – interruptions in breathing during sleep due to airway collapse
- space maintainer – dental appliance used to fill space of prematurely lost baby tooth to prevent shifting of surrounding teeth
- stomatitis – inflammation of mouth membranes